How to avoid picking the wrong sized plants for your North Texas landscape

It’s a question as old as the hobby of gardening. “How far back can I trim my plant?” We ask it because we failed to read the descriptions while we were shopping at the nurseries. We got home with plants that were intended for plantations, not for postage-stamp spaces. Now, here we are several years later, wondering what we can do with our overgrown giants.

It all goes back to genetics. We know not to choose a puppy with great big feet if we live in a studio apartment, yet we pack in shrubs that are programmed to grow 10 feet and taller and we plant them beneath 3-foot windows. You can probably see examples of live oaks planted alongside streets or up against houses. The saddest examples I’ve seen are bald cypress trees planted beneath power lines. Less than 10 years of age they’ve already been topped to keep them in bounds. You can’t take the top out of a conifer. It ruins its spirit to live.

Even shrubs can be size nightmares. Our poster children used to be redtip photinias before Entomosporium fungal leaf spot became epidemic without any good remedy. People would plant them beneath 3-foot windows, then they’d wince when I told them that the plants’ mature height was 15 to 20 feet and that pruning them to keep them beneath their low windows was only a dream.

I love crape myrtles as much as anyone, but I shiver when I see them planted 3 feet out from corners of houses. People find out a few years down the road that the variety they’ve chosen (for color without regard to mature size) grows to be 30 feet tall with 7-inch diameter trunks. That’s sad, because there are plenty of varieties that stay 7 or 8 feet tall. Or, if there was something really special about that one type they wanted, it could have been planted 10 or 12 feet out from the house so it would have had ample room to grow forever. But that is how we learn.

Our grandparents planted arborvitae on both sides of the front walk. That was part of the old-school “foundation planting” landscaping. They were used as focal points of the design to draw attention to the front door. They were beautiful for a while, but eventually they started to grow out over the sidewalk. Before long, people couldn’t see the front door at all, let alone penetrate the plants to ring our bells or deliver our mail. And that’s when the hedge shears came out. The arborvitaes were chopped bare. The sad part of it is that conifers like arborvitaes, junipers and cypress don’t send out new shoots when we cut back into their sides. Denuded once is denuded for life.

As a part of planting large shrubs in our landscapes we often resort to formal pruning to keep the plants smaller. Eventually that catches up to us as the shrubs begin to lose lower leaves and show exposed stems after the repeated trimmings. It may be time, then, to remodel the landscape entirely and start over with a new design, new and wider bed configurations, and different types of shrubs that will stay more compact. Do your homework ahead of time. Visit several nurseries and study the various choices. Talk to Texas Certified Nursery Professionals for their recommendations. Do your planning now for planting later this fall. With the small exception of winter-tender species, fall is the very best time of the year for landscaping.

Let’s say you have a prefabricated bed that’s only 3 or 4 feet wide, yet you want to conceal a wall or fence that’s 6 to 10 feet tall. That’s where you really need to be careful, because if you plant tall shrubs too close to the house, they’ll become flat-sided as they develop, and their roots will also present some amount of danger to the foundation as they suck water out during dry summers. If you plant them too close to the other side of the bed, they may grow into the driveway, alley or walk. Either way, you’re in trouble. That’s when it might be better to plant a clinging or clambering vine to go up the wall or fence and then to plant dwarf shrubs or groundcover at its base. You get the visual impact of tall shrubbery, but you don’t crowd into that valuable ground space.

And while we’re choosing the best plants for our landscapes, we might as well select types that will thrive in our soils. We can amend small amounts of topsoil for diminutive shrubs, groundcovers, annuals, and perennials, but when we plant large shade trees that require acidic soils we’re just asking for trouble. There’s no way we can import enough sandy loam topsoil to meet their long-term needs, and we certainly can’t keep adding iron and sulfur soil-acidifier to counteract the iron deficiency symptoms. We’re light years ahead if we just avoid species like East Texas pines, pin oaks, water oaks, sweet gums, and even dogwoods.

That is to say: stick with plant types that will be eager to perform for you. Leave the types that are likely to pout back at the nursery. Ask your nursery professional just before you lay down your payment, “Am I about to make a mistake with any of the plants you see in my wagon?” Let them own part of the decisions you’re about to make. They’ll be honest with their evaluations.